Formation mechanism of nano-strengthening particles in dispersion strengthened W-Ti Alloys

The realization of advanced fusion reactors rests upon improvements of plasma-facing materials for divertors. The toughness of tungsten is a critical issue for these improvements. As a solution, we developed dispersionstrengthened (DS) W-Ti alloys using a new process which is based on a combination of mechanical alloying (MA) and hot isostatic pressing. In this paper, the microstructure of new DS-W-Ti alloys and the formation mechanism of nano-strengthening particles are investigated. The produced DS-W-Ti alloys are dispersed with TiO2. The chemical analysis shows that new precipitation processes occurred during the MA based on redox reactions between carbon and oxygen. © 2020 The Japan Society of Plasma Science and Nuclear Fusion Research.